Click the 
Copy button in the Clipboard group on the Home ribbon tab.
Select the Copy context menu item of the cell or cell range.
Press CTRL+C or CTRL + INSERT.
On working with data in table area via clipboard, the following operations are available:
NOTE. Working with clipboard between browser tabs in the web application is available only via shortcuts. There may be some restrictions depending on the browser policy.
To copy cell values or selected cell range to clipboard:
Click the Copy button in the Clipboard group on the Home ribbon tab.
Select the Copy context menu item of the cell or cell range.
Press CTRL+C or CTRL + INSERT.
To cut cell values or selected cell range to clipboard:
Click the 
Cut button in the Clipboard group on the Home ribbon tab.
Select the Cut context menu item of the cell or cell range.
Press CTRL+X or SHIFT + DELETE.
To paste values of the cell or selected cell range from clipboard to the current table area location:
Click the 
Paste button in the Clipboard group on the Home ribbon tab.
Select the Paste context menu item of the cell or cell range.
Press CTRL+V or SHIFT + INSERT.
If pasted range is out of the table area, paste will be executed inside table area.
If the size of selected for paste cell range is less, the range size where data is pasted will be broaden right and button to the size of pasted range.
If the size of selected for paste range is greater, only the range corresponding to the size of pasted range will be filled in.
If the range is selected for cell paste, the range will be entirely filled with data from the cell.
See also:
Building Data Entry Form | Working with Ready Forms